My boss tried mobile, welcoming ring (6)
I believe the answer is:
Here is my best explanation:
'my boss' is the definition.
(I've seen this before)
'tried mobile welcoming ring' is the subsidiary indication.
'mobile' is an anagram indicator.
'welcoming' means one lot of letters goes inside another (in sense of \'inviting in\').
'ring' becomes 'o'.
'tried' anagrammed gives 'editr'.
'editr' placed around 'o' is 'editor'.
(Other definitions for editor that I've seen before include "One working on paper", "Publishing head", "The person who determines the final content of the newspaper", "one in charge of 10 [PRESS GANG] ?", "Media person", "Journalist in charge of publication", "Newspaper head", "One is responsible for publication", "Reviewer of text" and "Do tie out the newspaper head".)